Digging her own grave

[Allen]

She's not a hunting dog, but...

I know this is a forum for hunting dogs, so I hope I don't offend anyone with post.

Our family dog ( 1/2 black lab, 1/2 collie) is almost 10 years old and has just started digging up the back yard. We have been in this house for just over 1 1/2 years. She did dig some when she was a puppy but out grew it.

There is a new puppy ( pound mutt) that we got about 2 1/2 months ago. These two dogs love each other and play all the time, so I don't know if she is upset about the new dog.

What can I do to stop the digging?

Allen